The present invention relates to horizontal road-marking and in particular to light emitting horizontal road-marking tapes.
The problem of traffic safety, especially at night, has prompted a good deal of study and experimentation. A considerable contribution in the specific field of the horizontal road-marking has been previously made by the applicant.
There are two different kinds of road-markings, vertical road-markings and horizontal road-markings.
Horizontal road-marking is an especially challenging problem. Horizontal road-marking is important because it is situated within the arc of the human sight. In order to be efficient, horizontal road-marking has to be continuous. In order to maintain its efficiency, horizontal road-marking must also avoid diverting a motorist's attention to something different.
Anything different or anything needed from outside of the road-marking is negative and detracts from the safety efficiency of the marking because it diverts the motorist's attention from the road-marking itself.
In addition to numerous inventions regarding nighttime traffic safety, based on the use of retroreflecting elements, the applicant has also developed systems which incorporate their own light source. Under particularly foggy or misty conditions, the efficiency of such systems is superior to systems employing retroreflecting elements Retroreflective systems, however, have become increasingly efficient in recent years, also through developments made by the applicant.
The applicant has claimed the development of a marking tape that gives off its own light in his Italian Pat. Nos. 982.743 and 990.780, and in his corresponding U.S. Pat. No. 3,996,556. The light is produced by incandescent or fluorescent lamps or by luminous pigments activated by visible and even non-visible light.
On the one hand, however, these light sources are not well suited for sustaining the stress of traffic and, in addition, have rather short service lives when kept constantly lit, say, during the nighttime hours. On the other hand, there is the consideration of the required current, especially if it is necessary to use, in the practical case, storage batteries to supply this current.